One of the best RTS expansion packs since Starcraft Broodwar
Other than adding new races, each of the previous races gets a new unit, the Imperial Guard the heavy weapons squad which starts out as a heavy bolter placement and can be upgraded to either an Auto Cannon or a Lascannon, the Space Marines get the Grey Knights squad which are good against Chaos daemons they also have superior close combat capabilities, the Eldar get the Harlequin which is good in close combat, has the ability to disrupt enemy squads and can kill an enemy unit with the Harlequin's kiss, Chaos gets the Daemon prince which is an enormous Daemon that slaughters units with its amazing close combat abilities, and the Orks get the Flash Gitz which gives the Orks a well needed boost in far ranged capabilities. With addition to new units there are new technologies and unit restrictions for example the Space Marines can only build one terminator squad, while the Orks get a technology that gives them the ability to bring out Slugga Boyz for free. Also something else worth mentioning is how the infiltration system has been redone, before the technology to research infiltration was cheap and all one had to do was click the squad which had infiltration abilities and click on the icon and the unit would be undetectable by enemy units, the infiltration went away if the squad was detected by a turret or an enemy Sergeant or higher ranking officer which made the ability fairly useless, now the way infiltration works is that the initial research of the ability is increased significantly but when the research is completed the squads with the infiltrated abilities are already infiltrated and only certain units and buildings can detect infiltrated units. Also as a side note the graphics engine has been cleaned up, the effects of explosions and guns firing looks a lot better. It does not take a huge rig to get this game looking and playing nice.
The best feature about the game is the campaign, instead of the campaign being linear and doing a bunch of missions for the race you choose, when you choose a race for the campaign you are shown an intro movie for the race you have chosen and a map that resembles a risk board. The battle for the campaign takes place on the battle Kronus and all 7 races of the game want Kronus for its own needs. It is turn based, you can attack once with your commander or move your commander once. You start off with a couple of territories and your stronghold, the stronghold is the main territory for each race and if it falls that race is removed from the campaign also each stronghold has a different condition for taking the stronghold such as killing a commander, to win the campaign for the race you must defeat all the other races strongholds.. Each territory has a number on it which represents the strength of the territory. You start off with a commander and as you conquer more territories you will get units to add to his honor guard, when you hire an honor guard unit it will start the battle with you commander. At the beginning of each turn you are given planetary requisition equal to the value of each territory you own, you can use this to hire units on your territory to defend it if anyone attacks it. The gameplay for each battle is just like a skirmish map except the condition is to destroy your enemies command center, if you are victorious whatever building you built on the planet is already placed there so you can start building units if you are attacked. Dawn of War Dark Crusade is easily one of the best expansion packs ever released for an RTS in quite some time, with the amount of content on it the game never seems to get boring and will entertain gamers for long amounts of time. If you are a fan of Warhammer 40k, a fan of RTS games, or want to try something different I recommend buying this game.